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authorSean Christopherson <seanjc@google.com>2021-12-07 23:09:19 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2021-12-10 13:12:42 +0100
commit3244867af8c065e51969f1bffe732d3ebfd9a7d2 (patch)
treef557e5a7887b52de0862b0f59055c7c1a0028976 /arch
parentKVM: x86: Wait for IPIs to be delivered when handling Hyper-V TLB flush hyper... (diff)
downloadlinux-3244867af8c065e51969f1bffe732d3ebfd9a7d2.tar.xz
linux-3244867af8c065e51969f1bffe732d3ebfd9a7d2.zip
KVM: x86: Ignore sparse banks size for an "all CPUs", non-sparse IPI req
Do not bail early if there are no bits set in the sparse banks for a non-sparse, a.k.a. "all CPUs", IPI request. Per the Hyper-V spec, it is legal to have a variable length of '0', e.g. VP_SET's BankContents in this case, if the request can be serviced without the extra info. It is possible that for a given invocation of a hypercall that does accept variable sized input headers that all the header input fits entirely within the fixed size header. In such cases the variable sized input header is zero-sized and the corresponding bits in the hypercall input should be set to zero. Bailing early results in KVM failing to send IPIs to all CPUs as expected by the guest. Fixes: 214ff83d4473 ("KVM: x86: hyperv: implement PV IPI send hypercalls") Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com> Message-Id: <20211207220926.718794-2-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/hyperv.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 5e19e6e4c2ce..8d8c1cc7cb53 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -1922,11 +1922,13 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool
all_cpus = send_ipi_ex.vp_set.format == HV_GENERIC_SET_ALL;
+ if (all_cpus)
+ goto check_and_send_ipi;
+
if (!sparse_banks_len)
goto ret_success;
- if (!all_cpus &&
- kvm_read_guest(kvm,
+ if (kvm_read_guest(kvm,
hc->ingpa + offsetof(struct hv_send_ipi_ex,
vp_set.bank_contents),
sparse_banks,
@@ -1934,6 +1936,7 @@ static u64 kvm_hv_send_ipi(struct kvm_vcpu *vcpu, struct kvm_hv_hcall *hc, bool
return HV_STATUS_INVALID_HYPERCALL_INPUT;
}
+check_and_send_ipi:
if ((vector < HV_IPI_LOW_VECTOR) || (vector > HV_IPI_HIGH_VECTOR))
return HV_STATUS_INVALID_HYPERCALL_INPUT;